heater core bypass?
 

has anyone ever done a heater core bypass??? did you see better mpg from it?
i think it would help without

If you have a really short commute it may be worth while to look into. Other than that I don't see it having much effect.

oh well your probably right :(

Any idea how much coolant the heater core holds? I think my entire coolant system for my ~1.5L engines hold about 1 gallon. If we get a few numbers on things we can calculate what % of thermal mass the coolant in the core consists of versus the coolant in the engine and the thermal mass of the engine.

6 liters well im thinking about how the coolant is circulating all the time

Yeah I understand. By bypassing the heater core you would lessen the initial amount of thermal mass you need to heat to get the engine up to temperature which means you get up to temperature faster. Its not a bad idea, we just have to determine if we're actually reducing that by any notable amount. My initial guess is probably not, but it can be calculated.

My heater core has a valve on it that it only opened up when the heat is turned on.

My cars do also.

I've read on performance sites that a heater bypass can cause hot spots in the engine due to changed coolant flow.
It's better to simply block the coolant lines to the heater if you want to remove it.

ya your right on :) wait how can we calculate it?

cool! what kind of car you got? can i buy the value aftermarket? for say a 97 nissan pickup lol